Sealing machine



Jan.19,193 7. l F. o. S'TAVES l 2,068,439

SEAL-ING MACHINE Y Fild Feb. 5, 1956 mmmmmmmi Patented Jan. 19, 1937 UNITED STATES YPATENT GFFICE SEALING MACHINE tion of Massachusetts Application February 5,

3 Claims.

This invention relates to an apparatus for seallng containers, such as liber board cartons having inwardly folding flaps adapted to be secured in closed position by any suitable adhesive. In packaging goods in ber board cartons, it is the usual practice to seal the flaps by means of an adhesive, such as a vegetable or animal glue, which requires an appreciable period of time to penetrate the surface of the flaps and become "set sufficiently to hold the flaps in closed position. In order to insure a satisfactory penetration and setting of the adhesive, it is the practice to use a sealing means having a presser head which clamps the aps of one or more cartons for a period of time suflicient to insure a penetration and setting of the adhesive. With machines of this type the sealing operation is carried out in batches, and for this reason not only necessitates considerable handling, but also is quite apt to slow down production. Moreover, in machines of this type the presser head clamps down upon the flaps carrying the adhesive suddenly and subjects'them to a pressure which often causes a substantial amount of adhesive to be forced from between the aps before it has had time to penetrate, thereby producing a much weaker bond than would have been produced if the adhesive had been allowed to penetrate before being subjected to pressure.

The principal objects of this invention are to provide a sealing machine which overcomes the aforementioned deficiencies of prior machines and which is designed for continuous operation; to provide a sealing machine capable of operating on cartons of widely varying size, and which is so designed that the period of penetration of the adhesive and the pressure applied to the flaps carrying the adhesive may be varied so as to produce the most effective bond; and to provide a sealing machine which is of simple construction, reliable and efficient in operation, and which may be operated in conjunction with any of the conventional types of gluing machines and conveyors.

Further objects of the invention will be apparent from a consideration of the following description and accompanying drawing, wherein- Fig. 1 is a side elevation of a sealing machine constructed in accordance with the present invention; i

Fig. 2 is an end View of the machine;

Fig. 3 is an enlarged detail view of a part of the adjusting mechanism for the upper run; and

Rigs. 4 and 5 are fragmentary views showing a 1936, Serial No. 62,460

modified arrangement for adjusting the position of the lower run.

'I'he embodiment chosen for illustration comprises two pairs of spaced uprights I and 2 which are preferably U-shaped in cross section, the "-5 lower and upper parts of each upright being formed with elongate slots 4 and 5, respectively.

A lower frame member, designated generally by the numeral 6, is supported by the uprights and comprises a pair of spaced angle irons 'I and 8 l0 rigidly secured to a pair of spaced cross bars 9 each having depending ears I6 at each end, the ears being positioned slidably to engage the inner faces of the uprights I and 2. A plurality of rollers I6 are journaled in any suitable mannerl in the upright wings of the angle irons 1 and 8 and constitute the lower run of a conveyor which supports the cartons C being sealed. The front and rear ends of the frame may also be provided with transverse members I2 and I 4 and a plu-y 20 rality of intermediate braces I5 may be provided to increase the rigidity of the frame.

As above noted, the depending ears I6 of the cross bars 9 are disposed in alignment with the uprights I and 2 and each of these ears is pro-r 25 vided with an opening which receives the shank of 'a bolt or machine screw I8 which projects from the inner side of the ears I8, as shown in Fig. 2. Each bolt has a threaded engagement with an inwardly directed lug I9 which is slid-` able in the lower slot 4 and which is integral with 30 a collar 26 having a vertically extending threaded bore. A lower bearing member 2| is rigidly secured to each of the uprights adjacent to its lower end and an upper bearing member 22 is rigidly secured to each upright between the slots 4 and 5. Each pair of bearings 2| and 22 support a screw shaft 24 which carries a collar 20. The lower end of the screw shaft carries a bevelled gear 25 meshing with a gear 26 secured to any operating shaft 28 which is journaled in bearings 29 and 30 secured to the uprights. One end of the operating shaft is squared or otherwise shaped to receive a crank (not shown) by means of which the screw shafts may be rotated so as to raise or 4 lower one or both ends of the frame member 6 to any desired height or angle of inclination, as indicated by the dot and dash lines of Fig. 1.

In the modied construction shown in Figs. 4 and 5 the uprights Ia are provided with a plu- 50 rality of spaced openings 32 in place of the slots 4 and the bolts I3 project through these openings and receive nuts 33 which lock the parts in any position of adjustment. The openings 32 `may be spaced apart a distance of the order of 55 one inch and may extend from adjacent to the lower end of each upright to the slots 5 so that the lower frame member may have a wide range of adjustment.

A transversely extending yoke 35 is secured to the upper ends of each pair of uprights and each yoke is provided with a central opening which receives a, collar 36 having a screw-threaded bore. A screw bar 33 is carried by the collar 36 and projects downwardly through an opening 39 (Fig. 3) in a U-shaped bracket 48. The upper end of the screw bar is provided with an operating wheel 42 by means of which it may be raised or lowered and its lower end is shaped to provide a stem 43 of reduced diameter. The stem 43 carries a washer 45 which engages the shoulder 44 surrounding the stem and also the marginal portion surrounding the opening 33 in bracket 48, as shown in Fig. 3. The bracket is rigidly secured to another bracket 46 by screws 41 and the bracket is provided with a centrally disposed opening or recess 48 in alignment with the end of the stem 43, as shown in Fig. 3. A coil spring 58 is circumposed about the stem 43 with one end abutting the washer 45 and its other end being seated in the recess 48. The spring 58 is normally compressed suiciently to hold the washer 45 against the underside of the bracket 48 and shoulder 44 and the end of the stem 43 is thus normally held in spaced relation to the bottom of the recess 48 so that the spring 50 is operative yieldingly to oppose upward and downward movement of the bracket 48 and associated parts, relative to the screw bar and uprights. The distance between the end of the stem 43 and the bottom of the recess 48 may be of the order of V8 of an inch so as to permit a slight upward displacement of the brackets and associated parts, relative to the screw bar.

The bracket 46 supports an upper frame member, designated generally by the numeral 60, which comprises a pair of spaced angle irons 8| and 62 rigidly secured by a plurality of transverse braces 64. The wings of the angle irons 6i and 52 extend downwardly and rotatably support a plurality of rollers 65 constituting the upper run of the machine. The rst roller at the front end, and preferably the rst two or three rollers, may be either mounted in vertically extending slots 6B or provided with lioating bearings so that it is vertically movable relative to the frame member 3D. Laterally extending lugs 68 are secured to the frame member 6B, these lugs projecting into the slots 5 in the uprights l and 2 to guide the frame member B8 during its movement toward and away from the lower frame member 6 and also to oppose any tendency of. the frame member 60 to sway longitudinally during the sealing operation.

In using a machine constructed in accordance with the present invention the upper and lower frame members are rst adjusted in accordance with the size or height of the cartons to be sealed. For example, if the height of the cartons to be sealed is twelve inches when the flaps are in closed position, the screw bar 38 may be so adjusted that the distance between the front rollers of the upper and lower run is twelve to twelve and one-quarter inches and the distance between the rear rollers of the upper and lower run is eleven and three-quarters to twelve inches. When Y thus adjusted the end of each stem 43 is spaced from the bottom of the recess 48 so as to permit an upward displacement of the frame which will prevent any danger of crushing the cartons.

The aps of the cartons are provided with a layer of adhesive in the usual manner, this operation either being performed automatically or manually, and the aps are then folded inwardly and the carton is then conveyed or carried to the lower run and fed or pushed between the rollers of the upper and lower frames. As the rollers at the front of the machine are supported in floating bearings or the like, they exert but little pressure on the flaps and merely serve to hold them in closed position so that the adhesive will have time to penetrate the surfaces of the flaps. As cartons C are pushed or conveyed toward the rear or exit end of the machine, the intermediate rollers of the upper and lower runs, being successively closer to each other, exert a lgradually increasing pressure and when the cartons reach the rollers at the rear or exit end of the machine the maximum pressure is exerted thereon due to the fact that the cartons eiect an upward displacement of the upper frame member and not only sustain the entire weight of the rear end of the frame but also are subjected to the force resulting from the action of the spring at the rear of the machine, which yieldingly opposes the upward displacement of the frame 6U. It is thus apparent that as the cartons move from one end to the other, their inturned flaps are subjected to a gradually increasing pressure which may be varied by manipulating the screw bars 3B so as to vary the distance between the upper and lower run of rollers.

If desired both the upper and lower run of rollers may be inclined so that during the sealing operation the cartons may be conveyed from one level to another. The cartons may be carried or pushed through the machine manually or automatically, and in either case their movement may be facilitated by positioning the upper and lower run so that they are downwardly inclined there-` by utilizing the action of .gravity without impairing the aforementioned function.

It will be noted that in using the machine constructed in accordance with the present invention the sealing operation may be carried on as=` a continuous operation, as distinguished from batch operations, and that the sealing operation when thus carried out dispenses with supervision and laborious handling of the cartons.

While I have shown and described one desirableembodiment of my invention it is to be understood that this disclosure is for the purpose of illustration only and that various changes in shape, proportion and arrangement of parts, as well as the substitution of equivalent elements for those herein shown and described, may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

l. A sealing machine comprising upper and lower frame members, the upper frame member being mounted for independent vertical movement toward and away from the lower frame member, a plurality of rollers rotatably supported' by each of said frame members, and means for yieldingly supporting said upper frame member for movement toward and away from said lower frame member, said means comprising a bracket secured to said upper frame member, a horizontally disposed yoke rigidly supported above said bracket, a vertically disposed screw shaft carried by said yoke, and connections between the lower end of said screw shaft and bracket including resilient means operative normally to hold the' end of said screw shaft spaced from said bracket and yieldingly to oppose vertical movement of said upper frame member.

2. A sealing machine comprising upper and lower frame members, the upper frame member being mounted for independent vertical movement toward and away from the lower frame member, a plurality of rollers rotatably supported by each of said frame members, and means for yieldingly supporting said upper frame member for movement toward and away from said lower frame member, said means comprising a bracket secured to said upper frame member, a horizontally disposed yoke rigidly supported above said bracket, a vertically disposed screw shaft carried by said yoke, and connections between the lower end of said screw shaft and bracket including a spring, one end of which is superposed about the lower end of said screw shaft and its other end arranged to engage said bracket, thereby yieldingly to oppose upward movement of said upper frame member, and means associated with said spring for supporting said bracket so as to permit a limited upvvardmovement of said upper frame member.

3. A machine for sealing cartons, comprising a plurality oi upright supports, an elongate lower frame member adjustably secured adjacent to each end to said upright supports so that its position relative to a horizontal plane may be varied, an upper frame member, a plurality of rollers rotatably supported by each frame member, adjustable means carried by said upright supports and connected to said upper frame member adjacent to its ends, said means being constructed and arranged to vary the position of said upper frame member relative to a horizontal plane independently of said lower frame members so that the relative position of the upper and lower :frame members may be varied in accordance with the desired pressures to be exerted on cartons passing between the rollers carried thereby, and means associated with said adjustable means and upper frame member operative yieldingly to permit a predetermined upward displacement of said upper frame member.

FRANK O. STAVES. 

